60 research outputs found
Self-Consistent Field study of Polyelectrolyte Brushes
We formulate a self-consistent field theory for polyelectrolyte brushes in
the presence of counterions. We numerically solve the self-consistent field
equations and study the monomer density profile, the distribution of
counterions, and the total charge distribution. We study the scaling relations
for the brush height and compare them to the prediction of other theories. We
find a weak dependence of the brush height on the grafting density.We fit the
counterion distribution outside the brush by the Gouy-Chapman solution for a
virtual charged wall. We calculate the amount of counterions outside the brush
and find that it saturates as the charge of the polyelectrolytes increases
Infant mortality in mid-19th century Amsterdam:Religion, social class, and space
This study uses a unique historical GIS dataset compiled from birth, death, and population register records for infants born in the city of Amsterdam in 1851 linked to microālevel spatial data on housing, infrastructure, and health care. Cox's proportional hazards models and the concept of egocentric neighbourhoods were used to analyse the effects of various sociodemographic characteristics, residential environment, water supply, and healthācare variables on infant mortality and stillbirth. The analyses confirm the favourable position of the Jewish population with respect to infant mortality as found in other studies and show the unfavourable position of orthodox Protestant minorities. Infant mortality rate differences are much smaller between social classes than between religions. The exact role of housing and neighbourhood conditions visāaāvis infant mortality is still unclear; however, we ascertained that effects of environmental conditions are more pronounced in later stages of infancy and less important in the early stages of infancy
Salt Dependence of the Tribological Properties of a Surface-Grafted Weak Polycation in Aqueous Solution
The nanoscopic adhesive and frictional behaviour of end-grafted poly[2-(dimethyl amino)ethyl methacrylate] (PDMAEMA) films (brushes) in contact with gold- or PDMAEMA-coated atomic force microscope tips in potassium halide solutions with different concentrations up to 300Ā mM is a strong function of salt concentration. The conformation of the polymers in the brush layer is sensitive to salt concentration, which leads to large changes in adhesive forces and the contact mechanics at the tipāsample contact, with swollen brushes (which occur at low salt concentrations) yielding large areas of contact and frictionāload plots that fit JKR behaviour, while collapsed brushes (which occur at high salt concentrations) yield sliding dominated by ploughing, with conformations in between fitting DMT mechanics. The relative effect of the different anions follows the Hofmeister series, with I ā collapsing the brushes more than Br ā and Cl ā for the same salt concentration
The Link Between Suggestibility, Compliance, and False Confessions: A Review using Experimental and Field Studies
Expert witnesses and scholarssometimesdisagree on whether suggestibility and compliance are related to peopleās tendency to falsely confess. Hence, the principal aim of this review was to amass the available evidence on the link between suggestibility and complianceand false confessions. We reviewed experimental data in which false confessions were experimentally evoked and suggestibilityand compliancewere measured. Furthermore, we reviewed field data ofpotential false confessions and their relationship with suggestibility and compliance. These diverse databases converge to the same conclusion. We unequivocally found that high levels of suggestibility (andto a lesser extentcompliance)were associated with an increased vulnerability to falsely confess. Suggestibility measurements might be informative for expert witnesses who must evaluate the false confession potential in legal cases
Adsorption of ionic block copolymers: self-consistent-field analysis and scaling predictions.
āSimulation of Risks for Monitoring and Preventionā,
This paper deals with a tool developed to support training and education in the field of security and safety in work areas, plants, or industrial environments. The tool comprises the dashboards enabling administrators and users to simulate risks and accidents to be ready for interventions in case of occurrence. Based on a computational model of risks, able to identify the causes and the signs/indications which precede accidents, and to enact prevention mechanisms, and to execute repair actions in order to avoid accidents, this paper presents a Risk Simulation Management (RSM) system and its functioning on some examples
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